1990 Is Not 1933

REFLECTIONS ON THE REVOLUTION IN EUROPE. By Ralf Dahrendorf, New York: Times Books, 164 pp., $17.95 TWO STATES - ONE NATION. By G"unter Grass, New York: Harcourt Brace Jovanovich, 123 pp., $18.95

`FROM this moment begins a new era, and you are present at its birth.'' So announced Goethe in 1792, as French revolutionary armies decisively repelled those of the ancien regime. And so it has been since last autumn in Central and Eastern Europe. The unification of the two halves of Europe and particularly of Germany has ended that legacy of World War II, the Yalta system of armed spheres of influence.

A less obvious revolution-and-unification also has happened, as Ralf Dahrendorf suggests in his extended essay, ``Reflections on the Revolution in Europe'': that of thought and attitudes, language and expression. Traditional Marxist jargon has evaporated overnight, along with the ruling class that employed it.

Those stultifying code phrases that George Orwell mocked - ``bourgeois nationalism,'' ``progressive forces,'' ``socialist motherland,'' etc., etc. - have ended in the historical trash can. Plain speaking has triumphed, as the indispensable first step toward creating a new society based on democratic institutions and the rule of law.

What are the chances of success? Dahrendorf is an authoritative judge. As an internationally renowned political sociologist; as an occasional participant in German politics; and as an heir to the social democratic tradition, Dahrendorf is well placed to go beyond the headlines and beneath the surface.

He is optimistic, albeit cautiously. Certainly, he is alert to ethnic rivalries, the demands of angry consumers, the urgent need for economic reorganization, and so on. The conventional wisdom has it that this crisis represents danger. To Dahrendorf, however, it represents a wonderful opportunity to build democracy among peoples heartily disgusted with the one-party, command-economy state.